


Entanglement

by prosodiical



Category: The First Fifteen Lives of Harry August - Claire North
Genre: Getting Together, Late Night Conversations, M/M, Mid-Canon, POV First Person
Language: English
Status: Completed
Published: 2018-09-14
Updated: 2018-09-14
Packaged: 2019-07-12 06:10:36
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,296
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15989279
Author URL: https://archiveofourown.org/users/prosodiical/pseuds/prosodiical
Summary: Harry August's sixth life has been tied to Vincent's since he argued his way into the spare armchair by the fire. What's a little more entanglement in this life?





	Entanglement

**Author's Note:**

  * For [Melody_Jade](https://archiveofourown.org/users/Melody_Jade/gifts).



> 99% of this is just conversation about 40s particle physics/time travel and ethics, sorry to say. 
> 
> I hope you like this!

Vincent's presence in my life had, in the last few months, exponentially grown. It wasn't uncommon for him to come to my rooms for a nightcap (mine) and conversation (largely his), and he drew me in with his brilliance as unaccustomed as I was to being accosted with such incisiveness. "Don't start with that again," I said, after we'd trod through the semi-familiar paths of quantum nonlocality to the many-worlds theory I supported, reformulated in a concession to the time period. "Ethically - "

"Ethically!" Vincent exclaimed. "Discussing the ethical implications of something not yet even past a scientific thought experiment is absurd - even if I should allow you that the philosophical ramifications of a theory might be worth discussing it is hardly necessary when considering experimental methods and means." 

"On that," I mused, nursing my Scotch, "I believe we must agree to disagree."

He huffed, folded his arms, then unfolded them and rose to his feet and started pacing in front of the fire in a fit of energy befitting his teenage years. "The paradox of your thought experiment - "

"Scientific, you said."

"If we are to consider it scientifically - as we well should! - you posit that time is nonlinear, and thus if we take into account the EPR paradox, surely that means you are suggesting that quantum entanglement may exist nonlinearly as well."

"It might," I allowed. "It would at least solve the dilemma of faster-than-light transmission. But if a particle entangled with the past is observed in the now - "

"Paradox!" He turned on his heel and narrowed his eyes at me, grey-green lit bright. "The best we can manage is an extrapolation; if cause and effect are to be time-independent..."

He considered it for a long moment, or perhaps he considered me. I raised my eyebrows at him. "Nevertheless, it was an ethical thought experiment, not a scientific one."

"You and your philosophical rubbish," he said, friendly despite his words, and he took the few steps between us and my glass from my hand, downing the remains of it in a gulp.

"Vincent," I said, curiously. He had reached for the bottle and refilled my glass, and did not return to his familiar armchair but perched himself on the coffee table before me. It put him at a disadvantage at height but close enough our knees bumped, and I studied him with thoughtfulness, the softness of his face limned by the firelight. "What are you doing?"

"Ethically speaking," he said instead of answering, and passed me back my glass, though not before taking another draught. "Are you asking how much responsibility this hypothetical time-traveller has to the result of his own actions? If we subscribe to the theory of alternate worlds it resolves the paradox of his existence, but then an entire universe hinges on an out-of-world traveller unable to be predicted by the past - a paradox in itself! Universal collapse. Or..."

"The chance to kill Hitler," I said, "or affect a linchpin in time in a positive way. Is complexity an excuse for inaction?"

His eyebrows were furrowed slightly. "Merely the act of travel will change time itself," he said, frustratedly. "If time is not robust to the act of observing - in your hypothetical example, Hitler might be killed through inaction just as well."

"So you favour action?"

"I favour _observation_ ," he said, "and experimentation. The time traveller has already affected the universe through the very act of travelling through time, so the question of action or inaction is irrelevant to them."

"Ethically speaking," I prompted, and he shook his head and bumped my knee with his.

"Ethically speaking," he repeated, "if the act of observation in itself affects the future and the past - if quantum entanglement might be nonlinear - we have already taken action, and the very spirit of scientific curiosity drives us to take more. As scientists, we have the expectation - no, the responsibility! - to observe, don't we?"

His cheeks were reddening, his eyes magnetically bright; he had grabbed my hands in his entreaty and dropped them only now, a little awkwardly. I was suddenly, uncomfortably reminded of some of the rumours travelling about campus about us, and examined Vincent in a not wholly unfamiliar light.

Was he handsome? Perhaps in passing, though I had never paid much attention to such things. What I had noticed - what had opened my door to him not the first, but every following time - was the challenge in his eyes, the spirit, as he said, of scientific curiosity, the way he had matched my memory of him with one of his own and the way our specialities distinctively overlapped. He was young, but with a maturity and expanse of knowledge that belied his age, and I found myself nowadays expecting his presence in my life, debating physics by the fire.

"So," I said, "you propose that the question of action vs inaction is inapt, because observation itself causes... the equivalent of wave function collapse."

In essence, being reborn - by being here, at Cambridge, now twenty-five years old - meant I might well have already stepped on the daisy and startled the sparrow and changed the universe. I remembered what Victoria had said about the cataclysm: Victor Hoeness and his war.

What if new kalachakra were born in his timeline, that one where so many were lost? If it was murder, I thought, to kill the existing kalachakra - if one's birth was reliant on some stepped-on daisy, would avoiding that daisy account to murder itself?

Had I changed Vincent Rankis, I wondered, and how much?

"Then," I finished, "ethically speaking, we all simply have the same responsibility - to society and ourselves."

"To the tenets of scientific discovery," he said with enthusiasm, leaning forward, "experimentation and observation, progress with considered thought - "

His hands were on my knees, almost but not quite inappropriate. "Vincent," I said, my eyebrows drawing together, "are you seducing me?"

His already-pink cheeks flushed pinker, but he met my gaze with impunity. "A thought experiment," he said, "the Copenhagen interpretation, Schrödinger's cat. Both states exist until observed."

I found myself smiling despite myself, at his brazen audacity in the face of this era's social mores. But it wouldn't have been without forethought; no doubt he had observed me already. "I'm observing you now," I said, raising my eyebrows in curious expectation. My voice came out lower than I had meant to, and Vincent's eyes gleamed in the low light, his smile sharp as a knife.

"Then, Dr August," he said, affecting my title even as he leaned in, his eyelashes casting shadows against his cheeks and his hands slipping further up to my thighs, "am I seducing you?"

"Vincent," I said, and it wasn't quite reproving. "Ethically speaking - "

I was cut off by his laugh, and then by his kiss. He'd risen with the coltish grace of a teenager but kissed me with fearless confidence, one hand on my shoulder and the other in my hair as his mouth slanted hard against my own. He tasted like my good Scotch and the warmth I'd almost forgotten before him, his unrelenting spark of drive and purpose temporarily redirected to the heated tug of his fingers against my scalp, the press of his chest against mine. He'd clambered into my lap, I realised somewhat belatedly, and he examined me from under lowered lashes when we finally broke apart.

His eyes were on my mouth. I said, "I hope you're not taking any of my classes this term."

"In the spirit of scientific inquiry," he started, grinning, and when I closed my eyes and affected a sigh he kissed me again, thorough and relentlessly bold. "Harry," he said, voice dropped a register, "am I seducing you?"

His face was flushed, his mouth red. "Yes," I said, "I believe you are."


End file.
